1. Field of the Invention
This invention relates to a method for cleaning teeth that utilizes an ultrasonic system. The ultrasonic cleaning method of the present invention comprises the application through a suitable medium of ultrasonic waves at a first frequency for a first period of time, followed by the application through the medium of ultrasonic waves at a second frequency for a second period time. The ultrasonic waves are preferably transmitted through a liquid medium which contacts the teeth. The ultrasonic waves form bubbles in the medium. The break up or disintegrate bubbles on contact with the teeth. This results in improved cleaning of the teeth.
2. Description of the Prior Art
For many years, manual toothbrushes were the predominant means for cleaning teeth. Manual toothbrushes typically have a plastic handle attached to a plastic head. Plastic bristles for cleaning the teeth are attached to the head. The motion required for cleaning the teeth is manually provided by the consumer.
While manual toothbrushes are effective to clean teeth, especially when combined with flossing, many consumers feel that the equipment and methods used in their dentist's office to clean their teeth are much more effective. Recently, many consumers have converted to using power toothbrushes.
Power toothbrushes are typically energized by a battery. The battery powers a motor having an output shaft which typically rotates or reciprocates. The rotation or reciprocation of the output shaft ultimately is converted into motion in the brush head of the toothbrush. Power toothbrushes with brush heads that reciprocate, rotate, and/or oscillate are all known in the art. While the power toothbrushes are seen as more effective at cleaning the teeth than manual toothbrushes, they are still not viewed as equal to the dentist's office cleaning equipment and methods.
Power toothbrushes with ultrasonic cleaning have recently been introduced to the market. These ultrasonic toothbrushes have a transducer that operates at a single frequency. Ultrasonic waves are transmitted from the toothbrush through a suitable medium to the teeth and gums. These ultrasonic toothbrushes are generally viewed as better at cleaning the teeth than conventional power toothbrushes, but still do not provide the same effective cleaning as the dentist's office equipment and methods.
U.S. Pat. No. 6,313,565 teaches a cleaning system that utilizes different frequency ultrasonic waves simultaneously applied to improve cleaning. The ultrasonic waves are generated by multiple transducers and may be at a frequency ranging from 9 kilohertz (kHz) to 5 megahertz (MHz).
Despite the disclosure of the above-mentioned reference, there is a continuing need for a tooth cleaning system that is more effective at cleaning the teeth.